Pennant sustained a groin injury just minutes into the 2-1 home win against Blackburn on Wednesday night and was substituted 37 minutes into the game whilst Heskey was replaced by match-winner Mikael Forssell just over an hour into the same game having picked up an ankle injury.
Manager Steve Bruce is already without the services of David Dunn (calf), Jiri Jarosik (hamstring) and Stan Lazaridis (groin) for Saturday's game at Goodison Park although midfielder Muzzy Izzet could return having missed the last two games with the knee injury he sustained in the away draw at Wigan at the beginning of the month.